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<CsoundSynthesizer>
<CsOptions>
</CsOptions>
<CsInstruments>
sr=44100
ksmps=10
nchnls=1
gifarn init 8 ; initialise integer for Farey Sequence F_8
gires fareyleni gifarn ; calculate length of F_8, returns 23
; the table length won't be a power of 2
; (The length of a Farey Sequence with n > 1 is always odd)
gilen init gires * -1
gifarey ftgen 200, 0, gilen, "farey", gifarn, 0
; initialize destiniation table with 0s
gifiltered ftgen 0, 0, gilen, 21, 1, 0
; initialize second destiniation table with 0s
gifiltered2 ftgen 0, 0, gilen, 21, 1, 0
; table filtering opcode: dest. source, mode, threshold
ginumpassed tablefilteri gifiltered, gifarey, 1, 6
; the threshold parameter indicates that denominators whose weights are heavier
; than 6 are not passing through the filter. The weight is calculated using
; Clarence Barlow's function of indigestibility of a number. According to this function,
; higher prime numbers contribute to an increased weight of any natural integer they divide.
; ginumpassed is the number of elements from the source table 'gifarey'
; that have passed the test and which have been copied to the destination table 'gifiltered'
; apply a different filter:
ginumpassed2 tablefilteri gifiltered2, gifarey, 2, 5
; In mode=2 we again test the digestibility of the denominators of the
; fractions in the source table.
; The difference to mode=1 is that we now let pass only vaules from the
; source that are as heavy as the threshold or greater.
instr 4
kndx init 0 ; read out elements of now filtered F_8 sequentially and print to file
if (kndx < ginumpassed) then
kelem tab kndx, gifiltered
fprintks "fareyfilter_lp.txt", "%2.6f\\n", kelem
kndx = kndx+1
endif
endin
instr 5
kndx init 0 ; read out elements and print to file
if (kndx < ginumpassed2) then
kelem tab kndx, gifiltered2
fprintks "fareyfilter_hp.txt", "%2.6f\\n", kelem
kndx = kndx+1
endif
endin
</CsInstruments>
<CsScore>
i4 0 1
i5 0 1
e
</CsScore>
</CsoundSynthesizer>
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